apfel



BEST AVAILABLE CP P. F. APPEL.

THSRMOSTATIC SWITCH.

APPUCATION HLED APR.4.1921.

atented Aug. 22, 1922 N 33 5 ffii 36 zi-- 3.7 22 23 ze l 30 s f 24 fi i f 2/ 2a /r Ej. 2 I 7 vunits stains PATENT OFFICE- PHILIP F. APFEL, OF SEATTLE, WASHINGTON, A SSIGNOR OF ONE-HALFTO WALDO E.

.. MATHER, OF SEATTLE, XVASHINGTON'. Y i

Application filed April vIt,

To all/whom z't may concern Be it known that-I, PHILIP F. Arran, a citizen of the UnitedStates, residing at Seattle, in the-county of-King and State of Washington, have 'invented certain l new and useful Improvements-in Thermostatic Switches, ofwhich the following is a specificationnl l .'v

This invention relates to electricjliquid heaters andfmore especially to ythermofstatically operated switches'forcontrolling4 the supply of the heating mediumtherefor.

The main obj ect of my invention is toprovide an apparatus of this character with improved switchcontrolling means actuated by variations ofthe liquid temperature for regulating the electric current or heating niedium to afford a substantially uniform temperature to the liquid during the operation ofthe heater.l

Another Objectis to provide apparatus of this nature in which the thermostat and the associated switch are contained within a housing which isA adapted to be connected with a pipe orother lliquid 'conduit through which liquid may flow.

A'further objectv isl to provide athermostatically operated switch provided with a novel means* 'for IYindicating whether the switch is in its open or closed condition.

The invention consists in the novel construction, adaptation; and combination of parts as will be hereinafter described and claimed.

In the accompanying drawings,-

Figure l is an elevational view, with parts broken away, showing an embodiment of the present invention applied to an electric water heating apparatus. Fig. 2 is a longitudinal vert-ical sectional view to an enlarged scale illustrating the thermostatic switch mechanism. Fig. 3 is a transverse sectional view through 3 3 of Fig. 2. Fig. i is a longitudinal sectional view showing a modified form of the invention.

In said drawings, the reference numeral 5 designates a shell or casing having water inlet and outlet openings at its opposite ends. As shown, said outlet extends through a threaded boss 6 which is connected with a hot-water service pipe 8.

The inlet to said shell is shown as an elbow 7 which is connected to the side outlet of a T-iitting 10 through which an electric heat- THERMOSTA'IIC SWITCH.

Specification of Letters Patent.

Patented Auglae, '1922.

1921. semi no. 458,375. ing element 11 extends into a water receptacle or tank 12.* 1g

Surrounding' the eleinentllin saidv T- fitting isa passage 13 affording communication between said tank-andthe shellv 5. Interiorly of said shell is a 4liquid tight-box having thin walls 14 of a high heat conducting-.metal which arespaced from-the' respective shell wallsffto lprovide water passages 15.1* A plate 16,-s'erves`1as-a removable wall-for both the`=shell and they boXand-'seats against packing'17 :which prevents any; leakage o f water thereat'. i l f Said box constitutes'a housing for a therl" mostat having a compound-'plate 18 made of two metals which'effectthe vbending of the plate byy their-unequal expansionbyincrements of heat. The thermostat plate has its ends seated against ythe en'ds2() of rigid supports 21.

Centrally of its length; said thermostat plate 4isconnected'to a rod22 whichis guided for reciprocatory movements in members 23 and 24 of a frame "which is rigid with the cover plate 16. f

` The frame member l2li-'is formed of an electric insulating material and'ha's secured thereto switch terminals'l26 and 27 which are engageable by a switch contact or closure plate and a set collar 28 o n'the rod 22 to produce vquick switch-opening movements to the contact 25 with respect to said switch terminals.

The circuit wires 31 and 32 for the electric heater 11 extend into the thermostat box, one of said wires beingr divided vand has the parts thereof respectively connected to the switch terminals 26 and 2T.

As illustrated in Fig. 27 the rod 22 is connected to an arm of a lever 33 which is fulcrumed intermediate its length by a pin 311 to said frame. This lever terminates in blade elements 35 and 36 arranged to be protruded by the reciprocatory movements of the rod through slots 37 and 371 of the cover plate 16 to indicate the open or closed positions of the switch contact as by means of suitable distinguishing colors or marks provided on the respective lever ends.

With the thermostatic'switch connected with an `electric liquid heater rand tankfin the manner illustrated and-described it oper- -rates automatically to cont-rol the flow oi-the electric, currentfto the heater. lVhen the Water in the tank cools, the-thern1ostat,-plate 18 is influenced by such temperature reduction to enable the saine to ail'ordaow 'ot' current to the electric heater. As the Water b'eenies' 'Warmer the' thermostat plate will bow outwardly with an. opening of the switch and cutting ott1 `the current to the l`By suitaiblv regulating theaboye described switch.controllingfmeclianisin it iis lapparent the .may 5be \controlle'd `to open fand close :the Theater. current `to `maintain the liquid .tait an approximately predetermined temperature.

vrth iftlieirinostatie isiapplied as shown-the 'tliermosteteyil-l beCaetuatedlby variations ini-,the :temperature of the Water invlthe tank even thouglifno i'vater is lbeing drawn ofi-:through the-pipe 8.`

In Fig. 4T have shown -a housing el-Ohaving an .inner box i or; receptacle '11 that is spaced -rom the y,Walls -thereotas .at 42 and containingjavthermostat member 3 of suhstantially the -formfshown @ne vend of .the thermostatw43` lis -securedf to the Ib'ox il ywhile. theiotlie'riend is. connected with -.a 'switch lei'ier 44 which is fulcrumed onya pivot 5i-5 1 ima switch housing 4 6.

. vThe switclifleverilt-carries apin 47 'Willich operatesfwithinia slot of an-.arin V48 Whit-.h

carries-a roller-1:50"on'itsllower end land is provided with a. compression spring 5l. The roller 50 l.rolls on yan .vz ircuate track-way andx-isarranged -to-.bridge theagap between two=-switch terminals :S31/and 54101? :i circuit wire f that ymay 'extend to an electric heater.

Vlien the. interior of the receptacle 4l is cool lthethermostat .43 will assume approximately .the shapeand position in which it is illustrated with 4a consequent closed circuit;v but as-the receptacle 41 becomes heated,

,taaie cci-T .Thedevice shown in fligdmay lie-con- .nected -With 'a liquidqheater in Substantially -the saine .manner .asthe device shownnrthe preceding figures. y .t Obviously changes in the form ,Q L r1 struction of this apparatus nay -be resented to Within thescopefotthe olloiviugclaini. i a 'WhatrIclaini,`is,-. I Apparatus of .the character. described, comp rising-.af housing-a liquidf.tiglitfije'cfpitacle. Aformed of' Arelatively Athin `heat conducting walls disposed within'said vhousing;and

spaced'itrom .the Walls thereof-toaliordinarL rou' passagewa'ys-or liquid,-liquid= inlet and outlet -u'ieans connected with said housing, a thermostat. plate .disposed .-Withinsaidre.- eeptacle in close proximity to a..\vall.there` of saitlplate beingadaptedtofb'e bowed-outw-.iidly by -a rise or temperature, switch stein connected jwith the central portion-.0f said plate,.spaced switch terminals adjacent said stem, a Contact :member on *said* stein lor bridging the gap between said' switch tenninals. and `.means connected "with fthe outer end oi" said switch stenifor indicating the open and closedposition of said switch.

Signed at Seattle7 lvasliington. thislth da); otvlaich-lfl.

PHILIP FABFEL.

ll-'Yitnesses Primm BARNES., MARGARET G. SUPPLE. 

